Dielectric coated aluminum panel siding



y 9, 1967 M. R. COLLINS 3,318,060

DIELECTRIC COATED ALUMINUM PANEL SIDING Original Filed March 13, 1962Fig. 3 9

INVENTOR. MARVIN R. COLLINS 22 j ATTORNEYS United States Patent3,318,060 DIELECTRIC COATED ALUMINUM PANEL SIDING Marvin R. Collins,Akron, Ohio, assignor to Alsco, Inc.,

Akron, Ohio, a corporation of Delaware Continuation of application Ser.No. 179,370, Mar. 13,

1962. This application Dec. 8, 1965, Ser. No. 517,178 8 Claims. (Cl.52-173) This is a continuation of my copending application, Ser. No.179,370, filed Mar. 13, 1962, now abandoned. This invention relates toaluminum siding panels and to wall facings comprising arrays of sidingpanels. Such wall facings are usually referred to as aluminum panelsiding.

Prefinished aluminum panel siding is generally provided withcorrosion-resistant protective coatings on both sides. These have adielectric property, and to obtain good electrical grounding of the wallit is necessary to provide an electrically conductive external rod orcable which is welded or otherwise electrically connected to the panelsand to a suitable ground connection. Such an installation is unsightly,particularly where provided on all four sides of a building. It may alsobe costly, particularly where its installation requires labor by adifferent trade or craft than that which is employed to erect the wall.However, such an installation is required when grounding of the aluminumpanel siding is necessary or desirable, such as where in the absence ofgrounding a lightning fire hazard exists, or where it is desired toexploit the conductance of the aluminum as an electrical shield againstlightning.

If the dielectric anti-corrosion coatings are omitted from the joints orjunctures between panels, electrical continuity of the wall may beachieved without an unsightly cable. However, these joints are moresusceptible to corrosion damage than other parts of the wall. Acids andalkalis deposited from moist air or contained in soil or other foreignmatter splashed 0n the wall by passersby tend to be more chemicallyactive where moisture lingers, where shelter against rainwater isprovided, and where the possibility of galvanic action is maximized. Allthese conditions occur at the joints between panels, particularly on theunderside of horizontal joints in aluminum panel siding which imitateshorizontal board siding.

Since the joints between panels are the most corrosionprone portions ofthe wall area, elimination of the corrosion-resistant coating at thesejoints has not been considered feasible, and the costly installation ofunsightly cables and the like has been necessary to achieve goodgrounding.

The present invention involves the concept of providing electricalcontact between adjacent panels along a line of electrical contact whichis contained interiorly of the panel joint so that all exteriorlyexposed panel portions are covered by the dielectric corrosion-resistantcoating. In one important aspect, the line of electrical contact isshielded against corrosive agents, and any corrosion that may occur iscontained by lines of dielectric contact space to each side of the lineof electrical contact.

In a more particular aspect, the invention contemplates the provision oflines of dielectric contact between adjacent panels on each side of aline of electric contact but below the line of electric contact so thatthe line of electric contact is the highest of the several contactingportions of the adjacent panels.

The drawings show one example of the invention as embodied in aparticular aluminum panel siding installation. FIGURE 1 illustrates abuilding having an exterior finish of aluminum panel siding. FIGURE 2 isan enlarged view of one of the horizontal panels of the siding ofFIGURE 1. FIGURE 3 is an idealized fragmentary end view on a stilllarger scale of two of the panels of the type illustrated in FIGURE 2and showing the joint formed between the two panels.

Shown in FIGURE 1 is a structure including walls having exterior sideswhich comprise aluminum panel sides. The walls may comprise a number ofaluminum siding panels 10 oriented in the horizontal direction tocomprise a horizontal board effect. There may be panels 30 oriented in avertical direction to give a vertical board effect as seen at thehighest portion of the wall structure. The upper and lower (side edge)joints or junctures or interlocks of the vertical panels 30 may beidentical with those of the horizontal panels to be described below, andare therefore not described in detail. If desired, the vertical panelsmay have protrusions formed adjacent one edge by extra folds to provideimitation batten strips 31. Otherwise, however the vertical panels maybe identical with the horizontal panels, including identity of interlockstructure as just mentioned.

One of the panels 10 is shown in somewhat enlarged view in FIGURE 2. Theprincipal area of the panel is bounded at the top by an upper edgeportion or joint portion generally indicated by the reference numeral 11and a lower edge portion or joint portion generally indicated by thereference numeral 12. Each panel 10' has a front face 8 and a rear face9. During manufacture, and before they are installed in a wall array,the panels 10 are provided with dielectric corrosion-resistantprotective coatings which may or may not be the same on the front andback faces of the panels. The dielectric corrosion-resistant protectivecoatings on the exterior side may comprise a paint or finish which isparticularly adapted to exterior exposure and exterior dress of thewall, while the interior coating or paint may be particularly adaptedfor the interior wall conditions and need not fulfill any decorative oraesthetic function.

It will be understood however that in some circumstances it may bedesirable to employ the same dielectric corrosion-resistant coating onboth sides of the panel. However in the illustrated structure theexterior dielectric corrosion-resistant protective coating is indicatedby a reference numeral 21, and a different dielectric corrosionresistantprotective coating is indicated for the interior side of the panel bythe use of a different reference numeral 22. Because of the scale of thedrawings, the coatings 21 and 22 are not indicated in FIGURES 1 and 2,and they are indicated on an exaggerated scale even in the greatlyenlarged scale of FIGURE 3.

Well known chemical primer coatings which are fairly good conductors mayunderlie the coatings 21 and 22. Due to their conductance, such coatingsare generally immaterial to the present invention and are not shown inthe drawings for the sake of clarity. However, it may be mentioned thatsuch primer coatings extend over all the metal and may have some valuein helping to inhibit corrosion.

In the vicinity of the lower edge 12 of each panel 10 a portion 14 ofthe rear face 9 is free of the dielectric protective coating 22 and isin interfacial contact with a portion 13 of the front face 8 of thelower panel of the pair in the vicinity of the upper edge 11 of thelower panel. The portion 13 of the front face 8 of the lower panel isfree of the dielectric protective coating 21 and there is therebyestablished a line of interfacial electrical contact 15 between theadjacent panels 10.

The remainder of the front and back faces 8 and 9 of the panels 10 arecovered by the dielectric protective coatings 21 and 22, with the panelsinterfacially contacting each other at lines of dielectric contact 16and 17. Nailing slots may be provided at 23 and drain slots at 24 asshown.

It will be noted that the lines of dielectric contact 16 and 17 arelocated at either side of the line of electrical contact 15. Each of thelines of dielectric contact 16 and 17 is spaced from the line ofelectrical contact 15 both in the sense that the lines of contact 16 and17 are laterally displaced aolng the facing surfaces 8 and 9 of the twopanels from the line 15 and in the sense that between the line ofcontact 15 and each of the lines of contact 16 and 17 the interfacialcontact between the two panels is interrupted. In the illustrated wallstructure, the line of electrical contact 15 is also located above thelines of dielectric contact 16 and 17.

The line of contact 15 is substantially completely sheltered against thedeposit of any corrosive materials, and is so locate-d that anycorrosion as may occur at this point will have little or no effect onthe appearance or performance of the aluminum panel siding.

With the particular configuration illustrated in FIG- URE 3 which ispresently preferred, it will be noted that the rear face 9 of theuppermost panel at the line of electrical contact is forwardly upwardlyoriented, while the front face 8 of the lower panel 10 at the line ofelectrical contact 15 is downwardly rearwardly oriented. The result isthat the products of any corrosion that may form at the line ofelectrical contact 15 will tend to fall within the pocket formed betweenthe contact lines 15 and 16, rather than into the pocket formed betweenthe lines 15 and 17, thus avoiding possible streaking of the exposedface 8 of the wall which might otherwise result if, lengthwise of thewall, the line of contact 17 were not an absolutely continuous seal sothat gaps existed through which or from which would extend verticalstreaks or discolorations caused by the products of corrosion.

The upper edge of the upper panel is interlocked with a still higherpanel and is exactly like the upper edge of the lower panel. The loweredge of the lower panel is interlocked with a still lower panel and isexactly like the lower edge of the upper panel.

The lowermost panels 10 may be grounded by cables 19 (FIGURE 1) whichare welded to these panels and are grounded through metal stakes 20 orother suitable grounding means. With the lowermost panels grounded, thelines of electrical contact 15 effectively establish grounding of theentire wall while themselves being shielded from corrosive agents by thedielectric lines of contact 16 and 17 as described above.

Upper, lower, upwardly, downwardly, above,

below, and like terms are used herein with reference to the horizontallydisposed siding rather than vertically disposed siding. This is purely amatter of language, but as a matter of substance some of the featuresdescribed herein do have more importance with respect to horizontallypositioned board than with respect to vertically positioned board, asfor example the location of the electrically conducting line of contactabove the dielectric lines of contact. However such features maycontinue to be important in vertical paneling, even though theirimportance may be diminished as compared to their provision inhorizontal paneling. Furthermore these features may assumenon-functional significance with respect to vertical panels to theextent that there may be substantial inventory advantages in providing asingle panel design which is capable of fulfilling all practicalrequirements of both vertical and horizontal installations or, even ifthe horizontal and vertical panels differ (as where a board-and-batteneffect is desired in the vertical panels), to the extent that there maybe costsaving manufacturing advantages in preserving the identity of thejoint structure and coating in both types of panels as in the exemplarywall described above.

The invention is not restricted to the slavish imitation of each andevery one of the details described above which have been set forthmerely by way of example with the intent of most clearly setting forththe teaching of the invention. Obviously, devices may be provided whichchange, eliminate, or add certain specific structural details withoutdeparting from the invention.

What is claimed is:

1. A wall comprising an array of similar elongated prefinished panels ofelectrically conductive material in parallel, overlapping relationship,each panel having a dielectric corrosion-resistant protective coatingwhich is applied thereto before the panels are installed in said array,adjacent pairs of panels in said array, each pair including a firstpanel and a second panel connected along their overlapping zone by aninterlocking joint, said interlocking joint including a first part ofsaid joint formed along said overlapping zone of said first panel havinga channel having opposed wall surfaces and a second part of said jointformed along said overlapping zone in said second panel, said secondpart projecting into said channel and engaging both of said opposed wallsurfaces thereof, portions of said first and second part providing saidengagement between said second part'and at least one of said opposedwall surfaces being free of said dielectric coating and providing anelectrical connection between each pair of panels along the interlockingjoint therebetween, all exterior surfaces of said panels being coveredby said dielectric coating, each panel being formed with a dielectriccoated portion between its exterior surface and its part of saidinterlocking joint, said dielectric coated portion of said first panelbeing in face-to-face adjacency with the dielectric coated portion ofsaid second panel along a zone adjacent to said interlocking joint sothat said interlocking joint is hidden from view from the exterior ofsaid wall and so that a barrier is provided to resist entry ofcorrosion-producing contaminants into said interlock and an electricalground connected to at least one panel of said array.

2. A wall as set forth in claim 1 wherein said panels extendhorizontally and said interlocking joint is located above saidface-to-face adjacency.

3. A wall as set forth in claim 2 wherein said channel is locatedadjacent the upper edge of said panel and is a downwardly open channel.

4. A wall comprising an array of similar elongated, prefinished panelsof electrically conductive material in parallel, overlappingrelationship, each panel having a dielectric corrosion-resistantprotective coating which is applied thereto before the panels areinstalled in'said array, adjacent pairs of panels in said array, eachpair including a first panel and a second panel connected along theiroverlapping zone by an interlocking joint, said interlocking jointincluding a first part of said joint formed along said overlapping zoneof said first panel having a channel having opposed wall surfaces and asecond part of said joint formed along said overlapping zone in saidsecond panel, said second part projecting into said channel and engagingboth of said opposed wall surfaces thereof, portions of said first andsecond part providing said engagement between said second part and atleast one of said opposed wall surfaces being free of said dielectriccoating and providing an electrical connection between each pair ofpanels along the interlocking joint therebetween, all exterior surfacesof said panels being covered by said dielectric coating, each panelbeing formed with a dielectric coated portion between its exteriorsurface and its part of said interlocking joint, said dielectric coatedportion of said first panel being in face-to-face adjacency with thedielectric coated portion of said second panel along a zone adjacent tosaid interlocking joint so that said interlocking joint is hidden fromview from the exterior of said wall and so that a barrier is provided toresist entry of corrosion-producing contaminants into said interlock, achemical primer coating provided on each panel along portions thereoffree of dielectric coating, said chemical primer coating providingelectrical contact while resisting corrosion along the portions free ofsaid dielectric coating and an electrical ground connected to at leastone panel of said array.

5. A panel for use as an external wall covering with similar,overlapping, parallel-arranged panels comprising an elongated sheetmetal base, a dielectric coating on said base, said panel being formedalong one longitudinal edge with a first part of an interlocking jointproviding a channel having opposed wall surfaces and along its oppositelongitudinal edge with a second part of an interlocking joint, saidsecond part being shaped and adapted to project into a channel andengage the opposed surfaces of a first part of a similar, parallel,overlapping panel and cooperate therewith to provide an interlockingjoint between such panels, said first part being provided with a firstportion on at least one of said wall surfaces which is free ofdielectric coating, said second part being provided with a secondportion free of said dielectric coating, said first portion beinglocated within said channel and shaped to provide electrical contactwithin said channel with a second portion of a similar, parallel,overlapping panel and provide an electrical connection between suchpanels along the length of the overlapping portions, the remainder ofsaid panel including all exteriorly exposed surfaces being covered withdielectric coating, said panel between each of said first and secondparts and its exteriorly exposed surface constituting dielectric coatedmeans for producing face-to-face adjacency of its exterior dielectriccoating with the exterior dielectric coating of a similar, parallel,overlapping panel adjacent to the contacting first and second portionsfor hiding said interlocking joint from view from the exterior of thepanels and for providing a barrier to resist entry of corrosionproducing contaminants into the area of such electrical connection whensaid panel is installed on a wall with similar overlapping andinterlocking panels.

6. A panel as set forth in claim 5 wherein said first part of saidinterlocking joint is formed by a first reverse bend causing said metalbase to extend back toward the adjacent edge, and a second reverse bendcausing said metal base to extend away from said adjacent edge, theparts of said panel extending from said second bend cooperating withsaid second bend to form said channel.

7. A panel as set forth in claim 5 wherein a chemical primer coating isprovided on said panel along the portions thereof free of dielectriccoating, said chemical primer coating providing electrical contact whileresisting corrosion along the portions free of said dielectric coatmg.

8. A panel as set forth in claim 7 wherein said chemical primer coatingis provided on substantially all of the surfaces of said sheet metalbase including the surfaces thereof under said dielectric coating.

References Cited by the Examiner UNITED STATES PATENTS 1,502,924 7/ 1924Stanley 174-2 1,732,779 10/1929 Stough 1742 3,159,943 12/1964 Sugar etal. 52-309 OTHER REFERENCES Modern Plastics, January 1952, p. ScientificLibrary call No. TP 986, AIM6.

Wethersfield, Conn, Ordinances, Amended Article XXIII, sec. 2316,subsec. 7L, adopted July 24, 1960, 2 pp.

FRANK L. ABBOTT, Primary Examiner. J. L. RIDGILL, Assistant Examiner.

4. A WALL COMPRISING AN ARRAY OF SIMILIAR ELONGATED, PREFINISHED PANELSOF ELECTRICALLY CONDUCTIVE MATERIAL IN PARRAEL, OVERLAPPING RELTIONSHIP,EACH PANEL HAVING A DIELECTRIC CORROSION-RESISTANT PROTECTIVE COATINGWHICH IS APPLIED THERE BEFORE THE PANELS ARE INSTALLED IN SAID ARRAY,ADJACENT PAIRS OF PANELS IN SAID ARRAY, EACH PAIR INCLUDING A FIRSTPANEL AND A SECOND PANEL CONNECTED ALONG THEIR OVERLAPPING ZONE BY ANINTERLOCKING JOINT, SAID INTERLOCKING JOINT INCLUDING A FIRST PART OFSAID JOINT FORMED ALONG SAID OVERLAPPING ZONE OF SAID FIRST PANEL HAVINGA CHANNEL HAVING OPPOSED WALL SURFACES AND A SECOND PART OF SAID JOINTFORMED ALONG SAID OVERLAPPING ZONE IN SAID SECOND PANEL, SAID SECONDPART PROJECTING INTO SAID CHANNEL AND ENGAGING BOTH OF SAID OPPOSED WALLSURFACES THEREOF, PORTIONS OF SAID FIRST AND SECOND PART PROVIDING SAIDENGAGEMENT BETWEEN SAID SECOND PART AND AT LEAST ONE OF SAID OPPOSEDWALL SURFACES BEING FREE OF SAID DIELECTRIC COATING AND PROVIDING ANELECTRICAL CONNECTION BETWEEN EACH PAIR OF PANELS ALONG THE INTERLOCKINGJOINT THEREBETWEEN, ALL EXTERIOR SURFACES OF SAID PANELS BEING COVEREDBY SAID DIELECTRIC COATING, EACH PANEL BEING FORMED WITH A DIELECTRICCOATED PORTION BETWEEN ITS EXTERIOR SURFACE AND ITS PART OF SAIDINTERLOCKING JOINT, SAID DIELECTRIC COATED PORTION OF SAID FIRST PANELBEING IN FACE-TO-FACE ADJACENCY WITH THE DIELECTRIC COATED PORTION OFSAID SECOND PANEL ALONG A ZONE ADJACENT TO SAID INTERLOCKING JOINT SOTHAT SAID INTERLOCKING JOINT IS HIDDEN FROM VIEW FROM THE EXTERIOR OFSAID WALL AND SO THAT A BARRIER IS PROVIDED TO RESIST ENTRY OFCORROSION-PRODUCING CONTAMINANTS INTO SAID INTERLOCK, A CHEMICAL PRIMERCOATING PROVIDED ON EACH PANEL ALONG PORTIONS THEREOF FREE OF DIELECTRICCOATING, SAID CHEMICAL PRIMER COATING PROVIDING ELECTRICAL CONTACT WHILERESISTING CORROSION ALONG THE PORTIONS FREE OF SAID DIELECTRIC COATINGAND AN ELECTRICAL GROUND CONNECTED TO AT LEAST ONE PANEL OF SAID ARRAY.